SRD3e:Read Lips Skill

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Read Lips (INT; TRAINED ONLY; ROGUE ONLY)

Check

The character must be within 30 feet of the speaker and be able to see her speak. The character must be able to understand the speaker's language. (Use of this skill is language-dependent.) The base DC is 15, and it is higher for complex speech or an inarticulate speaker. The character has to concentrate on reading lips for a full minute before making the skill check, and the character can't perform some other action during this minute. The character can move at half speed but not any faster, and the character must maintain a line of sight to the lips being read. If the check succeeds, the character can understand the general content of a minute's worth of speaking, but the character usually still misses certain details.

If the check fails, the character can't read the speaker's lips. If the check fails by 5 or more, the character draws some incorrect conclusion about the speech.
The DM rolls the character's check so the character don't know whether the character succeeded or missed by 5.